Multi-walled carbon nanotubes decorated CdO/Co3O4 hexagonal nanoplates: Unveiling their potential in hybrid supercapacitor

Abstract

A simple synthesis process for hybrid transition metal oxides is a crucial way for their application in energy storage system. In this work, multi-walled carbon nanotubes (MWCNTs) decorated CdO/Co3O4 hexagonal like nanoplates are prepared by fast emerging co-precipitation process. Further, CdO/Co3O4/MWCNT composite is used for energy storage performance and, specific capacity of 214.5 mAh g- 1 is obtained at 1 A g- 1. The capacity of CdO/Co3O4/MWCNT is found to be higher from the capacities of CdO (40.25 mAh g- 1), Co3O4 (100.5 mAh g- 1) and CdO/Co3O4 (171.63 mAh g- 1). Further, hybrid supercapacitor (HSC) is designed by CdO/Co3O4/ MWCNT (positive electrode) and activated carbon (AC) (negative electrode). The CdO/Co3O4/MWCNT//AC delivers the high energy density of 37 W h kg- 1 with the power density of 750 W kg- 1. In addition, to confirm the electronic applicability for portable appliances, four green color light-emitting diodes (LEDs), kitchen timer and toy motor fan are operated separately by two CdO/Co3O4/MWCNT//AC hybrid supercapacitor connected in series.